Leontes also is head-over-heels in love with his wife (Tamsin Egerton) and loyal to his king (Jamie Campbell Bower). He doesn’t know about their past affair, or that they struggle against reigniting the spark, which is apparent in the episode “Three Journeys,” debuting at 9 p.m. May 6. While Leontes goes on a mission for the king, Arthur accompanies Guinevere on a trip to see her ailing father.

The love triangle explodes later in the season, Winchester admitted. “It will get resolved in a very dramatic way. I can tell you that,” he said, joking: “We have a tap dance-off.”

I’m not sure about his dancing, but Winchester is no stranger to playing men who lose in love. In Fox’s “Fringe,” he guest stars as Fauxlivia’s ex, Frank, and in NBC’s long-gone “Crusoe,” he played the title role, a man living on a deserted island and lost to his wife back in England.

It was as that ab-baring, swashbuckling character that Winchester became widely exposed to American TV audiences. But thanks to Crusoe and subsequent roles, including in “Camelot,” many viewers believe he is British. “My mom’s English and she met a cowboy when she was on holiday in Montana,” he said, “and then I came along.”

The acting bug hit the Montana native early. Between riding horses on his grandfather’s ranch and family trips to Britain, he spent a lot of time with his father’s actor friends. His dad participated in theater at Montana State University, and would let his son hang out at rehearsals.

During high school, Winchester appeared in commercials and in the movie “The Patriot.” “It wasn’t the Mel Gibson one,” he said. “It was the Steven Seagal one, which is really embarrassing to say. I was 16 and I didn't know any better; it was my first movie.”

When he told his parents a few years later that he wanted to be an actor professionally, they said he had to train in England. So at 18, he packed up and headed to his grandmother’s bed-and-breakfast outside London and studied at The London Academy of Music and Dramatic Art. Eventually he spent a year working with the Royal Shakespeare Company, starring as Edmund in “King Lear.”

“When I left the States I had a full American accent,” he said, “but over the years … I just learned to pick up [an English accent] very quickly and use it.”

He may have gotten the accent right in London, but there was one thing he didn’t learn until filming “Camelot” in Ireland last year. He and the other actors playing knights perfected their sword fighting, horseback riding and other knightly skills at “medieval boot camp." But they also played hard, Winchester suggested.

“It is true what they say about the Guinness [in Ireland],” he said. “It tastes absolutely different. It’s creamier and smoother. You can put several down before you know you’ve done it. Not only were we on the ‘Camelot’ quest for protecting the king and all the Arthurian legend, but we were also on the quest for the perfect pint of Guinness, which we did quite often. We went looking for that as much as we could.”

Winchester, calling from Cape Town, South Africa, talked about “Camelot” and “Fringe,” his HBO/Cinemax project, doing the “knight workout” and how Va Va Voom the horse never, ever follows.

Arthur (Jamie Campbell Bower) and Leontes (Philip Winchester) in "Camelot." (Starz)Hi Philip. You're calling from South Africa?I am, yeah. My wife and I are out in Cape Town at the moment shooting a show for HBO ("Strike Back," which will air on Cinemax.)

I hear you did some extra “Camelot,” too?Yeah, that's right, we just finished a few pickups for “Camelot.” … “Camelot” came down here because I couldn't go back to Dublin to do pickups for that. So they flew their production down here. [Laughs.] Which is really cool, actually, because I get to see all the guys and everyone's really excited.

That’s cool they came to Cape Town.Well, it was really nice of them because I know they could've just cut me out of it. [Laughs.] But they were actually quite nice, and said, “We'll leave you in,” and they came down here. So it's great.

What are you shooting? Can you talk about it?We're doing a series called “Strike Back,” which is a—sorry, one second, I'm just going to grab something off my mate—thank you very much, I appreciate it. Sorry, it's my birthday and just got handed a lovely bottle of champagne.

Oh, happy birthday.Thanks buddy. So yeah, so it's called “Strike Back” and it’s actually their second season. It was on Skye [in Britain] originally. Richard Armitage was the lead in it and Daniel Percival directed it. HBO got wind of it and now HBO [Cinemax] and Skye have collaborated on it and … we’re doing six episodes in Cape Town and four episodes up in Hungary.

Cool. Didn’t you shoot “Crusoe” in South Africa?Yeah, that's right. We're not exactly in the same location geographically, but we're working with a lot of the crew and a lot of the same stunt people. So it's really great for my wife and I. It feels like we've come home, because there's a very tight community here. It's really neat.

I should tell you that I actually enjoyed “Crusoe.”[Laughs.] I like how you say that, because you know that not many people did.

I know, but I did. I liked it; it was fun.Well good, I appreciate that, mate. That’s exactly what it was supposed to be. I think we saw it kind of change after the third script … We thought, “Well, let's have fun with it.” And actually, it's lovely to hear that. Because the complements that we did get were along the line of, “An entire family can sit down and watch the show.” And that doesn't happen very often. So I think we made something that was accessible to more people than most shows. You know what I mean?

I do. Just a fun adventure show, sort of like the pirate movies I watched as a kid. But let's talk about “Camelot” and your character. He is not in the Arthurian legend that I can find. But is he supposed to be a new take on Lancelot?Well, it’s interesting. We had a lot of discussions on set. He’s not supposed to be Lancelot, but he’s supposed to have a lot of facets that Lancelot did have. What they've done with this series of “Camelot” is it’s pre-Round Table, it's pre-having the knights in any kind of assembled form. These guys are a rag-tag group of guys at the moment. Arthur is very young; he has his brother, Kay. The audience is trying to figure out whether Merlin’s good or bad. There’s Eva Green, who plays Morgana and she's always switching sides. It's very much the beginning of the Round Table and this group of men who stand for honor and justice.

And Leontes, he's actually a Shakespearian character, isn’t he? In the story that we're telling, he's originally one of the knights that guards King Uther. So Leontes, Brastias (Diarmaid Murtagh) and Ulfius (Jamie Downey) are actually taken from King Uther once he dies and they join Arthur's new assembly of men to become the new knights who will look after King Arthur.

So, the character of Leontes, in this, has a relationship with a very young Guinevere. And throughout the episodes you see that relationship develop and they've been betrothed to each other and they get married. That develops and, of course, that leads into the triangle of Leontes, Guinevere and King Arthur, which then again will lead into the love triangle of Guinevere, Arthur and Lancelot.

They’re sort of making Guinevere out to be a flanderer.[Laughs.] Well, I think it was always a bit of a risk. Tamsin Egerton, who plays Guinevere, is such a beautiful girl. And she's so charming and charismatic that, we always thought that would be a risk as well, but it just doesn't come off that way. She's so good at just being kind of humble and beautiful that you really buy her innocence. They certainly cast the right girl.

Were you a little worried about making this character who people might confuse with Lancelot.[Creator] Chris Chibnall and I sat down a lot and talked about the character, because I thought it does run the risk of walking a very fine line of becoming another character. However, they haven't introduced that character. So I thought, “Well, let's make him the knight who does protect Arthur.”

He is the leader of the knights. Let's make him that kind of person who has honor and who has integrity and really leads these men into places that really challenge them and we'll see what happens by the end of the series with him—whether he can continue that or not, especially if he finds out about the stuff with King Arthur. So he'll really be put to the test.

Guinevere and Arthur seem to feel bad about messing around, but not bad enough not to do it.[Laughs.] But not bad enough to stop, which is usually the case with things like that, isn't it? [Laughs.] It's funny because all three of us would get together and chat about this and say we have to make [their attraction based on] either the fact that he is the king or the fact that [Guinevere and Leontes] have been together so long that they know everything about each other and … it's reached that place where it's become commonplace. They know everything about each other. So this young kid comes along and he's also the new king who adds just enough to make it interesting to take her away for a while, to get her distracted.

Let’s about the sword fighting and horse work. You’ve done that before, but was it tricky anyway?I had, and obviously from “Crusoe,” done quite a bit of sword fighting, and I spent a year with the Royal Shakespeare Company and we did “King Lear.” I played Edmund and Edmund had a lot of sword fighting at the end of the show. I'd actually done this a few years, lots of sword fighting and things back to back to back. I did a film with James Purefoy called “Solomon Kane.” And so sword fighting was always there to tap into.

We had a really good group of guys to work with [on “Camelot”]. It was actually brilliant; they did kind of a boot camp, but a medieval boot camp version when we got there. Every morning on set we'd warm up and then sword fight for a few hours. We'd go horse riding in the afternoon out in the Irish countryside and learn how to bolt up horses and learn how to do some jumping, things like that.

And again, I think most of us had a bit of horse riding experience. I had horse riding experience for growing up in Montana. My grandfather had a ranch and so I grew up on a ranch with him and we’d get cattle and bring them in in the morning, things like that. We didn't have hunter horses or anything; we weren’t jumping. It was very basic stuff with big western saddles. So this was all quite new. It was all very posh and very proper.

Also, with the time period, the Dark Ages, there was potentially a huge amount of power and pomp and circumstance that went with the fact that you owned a horse and knew how to ride a horse. If you were a knight, this was a very big deal. So we kind of applied all that to these characters. These guys definitely were men—weathered, battled-hardened men. We tried to dredge up all that stuff and bring that into the training and to the sword fighting and horse riding. It was definitely good fun.

Your horse has quite a costume.[Laughs.] My horse’s name was Va Va Voom. That's such an appropriate name: Va Va Voom. [Laughs.] He is an ex polo horse. The thing that Va Va hated more than anything was to be behind another horse. He had to be in front. So when we had scenes where other guys were in front, like when Gawain was in front of me or Brastias or King Arthur, anyone else was in front of me, Va Va was underneath [me] just going crazy. I could feel her engine revving up. She just hated it. I would have to run her up to the front of the group just to calm her down and then we'd have to go back and start all over again. She's a great horse, though.

I remember during “Crusoe” you talked about how you sort of altered your workout regimen to fit the island and the things that would have been available to that character. Did you do that kind of thing in the medieval castles?[Laughs.] It's funny, actually, we had a really old-school personal trainer named Pat Henry. Pat Henry has trained tons and tons of people who've gone through Dublin and made films in Ireland. He's a wonderful man … He took us all under his wing. He took myself and Diarmaid Murtagh, the guy who plays Brastias, and Peter Mooney, the guy who plays Kay, and Clive Standen, who plays Gawain. He took us all under his wing.

He kind of made this thing we called the knight workout. And we were doing things typically that would be helpful for your upper body for sword fighting and riding horses and things like that. It wasn't as much as “Crusoe,” because I remember on “Crusoe” we were running sand dunes and doing things like that. We weren’t doing pull ups on the castle by any stretch of the imagination, but the workout with broadswords and then horse riding, and training with Henry was a different workout.

Each show kind of has its own flavor; each character needs to look at bit physically different from another character. So hopefully you get a couple of months or at least a month to try and change your body enough to become those people in a way that is more believable.

You seem to do all these very physically demanding roles. Is that something you try to do?I could be looking for them, I guess. When I read the scripts I see that there's the physical stuff in it. I just know that I enjoy it. I enjoy doing it and I enjoy the challenge of how it’s shot. Obviously what the audience sees is the character having a great sense of himself or of looking a certain way. But it's a huge collaboration. You have your personal trainer, you have your nutritionist, you have the camera team and the director picking the way you're going to move and the things you're going to do in the scene. So it is really a huge collaboration. And it’s lovely when it comes across on screen and people think, “Gosh, we really believe that.”

Let’s talk about the cast. How scary is Eva Green for real?[Laughs.] Eva Green, she was actually just lovely. She is such a lovely person. … To be honest with you, she is such a treat. She's so professional and she's breathtakingly gorgeous. So can you imagine Eva was up there and five, six, seven of these knights hanging around with each other, it was just—usually there was tons of banter going back and forth with each other and then Eva would step on set and you could hear a pin drop.

Yes she is. You have a lot more with Joseph Fiennes and the knights.Joseph Fiennes, he is fantastic. We had such a crack, especially being in Ireland where the atmosphere on the set, there was always a lot of banter going on between each other. We made fun of Joe being Shakespeare [in “Shakespeare in Love”] and things like that. He was brilliant. He’s such a good actor and made these great choices with Merlin. It was so great to stand beside him and watch him do things with this character. You just think, “Gosh, this guy is really good at what he does.”

But honestly the time we spent together as a group of guys, the knights, was great. Not only did we spend a bunch of time together on set, because the shooting hours for episode of television are just long and arduous, but we spent a lot of time in the pub. We spent a lot of time training. We spent a lot of time horseback riding. And if we weren’t on set, we were probably either out learning lines or doing auditions with each other or hanging out at the pub and watching rugby and just kind of getting a bit of the culture down. So the relationships were really deep. And that's why it's great to have more here now in Cape Town. It feels like this brotherhood kind of got back together again, because it's been a few months since we've seen each other.

Ireland looks gorgeous in the episodes. Did you get time to really see it?It's just so magical. It's absolutely brilliant. People in Ireland are just so hospitable. ...

Did you shoot in real castles or were those sets?They were sets. They did a fantastic job. It was over at Ardmore Studios where they’d done “The Tudors.” Morgan O’Sullivan … is just a wonderful producer. He's been doing it for years and years and years. Everyone respects him so much because he's kept the film business alive in Ireland. He brought in this amazing team of production designers. And they built the castle inside one of the sound stages; the great hall was inside the sound stage. And the exterior shots, they usually built the door, and a bit of the wall and then green-screened the rest of it on a cliff outside in the Wicklow Mountains just outside Dublin. So we did a lot of exteriors out in the mountains around Dublin, which was equally beautiful because I never imagined Dublin to be so rugged and vast. But it really is. You can drive outside Dublin in half an hour and you're in the luscious, greenest mountain you've ever seen. They're just beautiful.

Are we going to see Frank again on “Fringe”?I don't know is the real answer. It was funny, Frank came in about a year ago. And I got to meet with everyone and do some scenes with Anna [Torv] and stuff and we had a ball. And I was really pleased, and surprised to be asked back again and we developed the character a bit more. Then this big bombshell happened in the last stuff that I shot. [From Curt: Frank learned Fauxlivia was pregnant, with someone else’s kid.]

It was funny because I was filming “Camelot” and I would leave “Camelot” on a Sunday morning, get to Vancouver … Sunday night. I'd film Monday on “Fringe” and I'd fly back to Dublin on Monday night. So I would literally be in Vancouver for about 24 hours.

Shooting for 12 of those, probably.And we would shoot, we would literally shoot everything with Frank in it because I didn't have any time to be there. And then the last thing that we shot with Frank, the ultrasound and the bug man and all that stuff, we finished “Camelot” production on a Friday, I flew out Saturday, had Sunday to rest and learn lines. Then we shot Monday, Tuesday, Wednesday, Thursday, Friday all that stuff. It was on the last episode. So it was a bit crazy.

The only answer is that I don't know if we will see him back. I would love to go back. It is such a finely tuned machine out there. Everybody on the show is just tremendous. That's obviously why it's such a hit. They're just brilliant. But I don't know if we're going to see him again. I'm hoping there’s, because obviously we've seen Frank in the alternate universe, but it'd be fun to see him in this universe. It’d be fun to kind of explore what he'd be like.

Everyone thinks you are British, but you’re not … Is your wife, Megan, American?Actually, she's from Montana as well. We grew up together. Her brother and I were best friends growing up and her mom was my geometry teacher in high school and her dad was my baseball coach. We've known each other an awfully long time, so it seemed the right thing to do. We were best friends, and it's always a good thing to marry your best friend.

Was it “The Patriot” that gave you the taste for acting?It was quite a bit before that. My mom was working nights when I was younger at a nursing home and my dad was at Montana State University. … I'd go to the university with dad and just hang out back stage with actors.

And to be honest with you, I thought that was kind of what people did. I thought people told stories and also, being such a tight community of people, a lot of them were involved in this thing called Montana Shakespeare in the Parks, which Joel Janke directs and runs, they were a family to us. So we hung out with these people for years and years and years when I was a kid. I just thought that’s what people did. They told stories, they rectified things with sword fights, and they enjoyed life.

So I thought, “Why not give it a shot?” What was great was I had parents who said if you want to do it then do it. They didn't turn me away from it. So I was really fortunate there. A lot of people don't have that support. But I think my dad knew. He said, “I can't say no because I did it as well.” So it was probably from those years being a boy growing up in the theater in Montana and hearing Shakespeare in the Park and watching my dad do that with his friends.

What were your first professional gigs?I think the first thing I did when I was a kid was a Maxwell House Coffee commercial with George Strait. [Laughs.] And I did a Wrangler Jeans commercial, and then “The Patriot” came to town.

The director was a guy named Dean Semler, who was actually a [director of photography]. He DP’d “Dances with Wolves” and “Water World.” And then he went on to do “Apocalypto” with Mel Gibson. He kind of took me under his wing and said, “Look, you can do this for as long as you want, just keep your head on your shoulders and work hard and you can do this.”

I never forgot that it wasn't about being in the right place at the right time, which it can be a lot of the times. Don't get me wrong, but he really encouraged me just to work harder and never kind of let go of that. Even in those months and months and months you think, “This is the right job,” then you have a meeting and a screen test and it doesn’t go anywhere and you think, “Oh man, what am I doing wrong?” Even in those times I think back and just think, “Keep your head down, keep working.” That was very encouraging for me.